The Rot Doctor


Subject: I'm impressed.....
(cantilevered joist repair)
Date: Thu, 26 Jul 2007

You may remember that I have been patiently repairing joists of my cantilevered deck.

I invited a structural engineer to take a look at what I was doing. He suggested that I not invite the Building Inspector to take a look, but validated that your epoxy is my best shot at repair, short of major expense and rework to my house. He suggested that I also run a coat of L&L epoxy over the outsides of all my joists, not just the areas which show rot damage. His thought was to thoroughly protect the wood against any further deterioration due to moisture. This modest extra effort makes sense because if that wood fails, the cost of replacing these joists will be huge.

So. I got an autobody squeegee. I locally painted on a mix of L&L and sawdust, and then spread it thinly with the squeegee so that it filled all the small cracks that had opened in the wood due to drying. This went pretty quickly. My goal was to cover the whole outside surface of the joinsts and fill anything that represented a path into the wood. I left as thin a layer of L&L on the surface as I could, while forcing the stuff into all the cracks and crevices.

The result is an eye opener. I wish I had measured the deflection under load of these joists before they were treated, because they are now rigid as a rock. They are noticeably stiffer than they were before the L&L, and these joists had already been treated with CPES which also stiffened them. I am surprised that a thin layer of epoxy on the outside would make so much difference. I bet it soaked in and reinforced the wood surface making a much stronger structure.

Very nice stuff....

Charlie R.


Thanks for your comments. Yes indeed, epoxies are far stronger than the wood they replace, and our penetrating and slow-setting epoxies reinforce the wood, as you suggest.

We're glad that you are happy with the repair!